Sternocleidomastoid (SCM) Trigger Points

Introduction

The sternocleidomastoid (SCM) is a key neck muscle responsible for head rotation, flexion, and postural stabilization. When trigger points develop in this muscle, they can cause headaches, dizziness, jaw pain, and neck stiffness, often mimicking migraines, sinus pressure, or cervical spine dysfunction.

Name and Area

  • Name: Sternocleidomastoid (SCM)

  • Area: Located in the side of the neck, running from the sternum and clavicle to the mastoid process (behind the ear).

Indications

SCM trigger points may contribute to:

  • Headaches That Originate from the Neck and Travel to the Forehead, Temples, or Behind the Eyes

  • Pain or Tightness Along the Side of the Neck (Mistaken for Trapezius Strain or Cervical Spine Issues)

  • Dizziness or Lightheadedness (Can Mimic Inner Ear Dysfunction or Vertigo)

  • Jaw and Ear Pain (Can Resemble TMJ Dysfunction or Ear Infections)

  • Pain or Discomfort When Tilting or Rotating the Head (Common in Those with Poor Posture or Desk Jobs)

  • Increased Sensitivity to Bright Light or Screens (Common in Chronic Headache Sufferers)

Pain from this muscle is often mistaken for tension headaches, migraines, or cervical spine dysfunction.

Muscle Action

  • Rotates the Head to the Opposite Side: Allows looking over the shoulder.

  • Flexes the Neck Forward: Tilts the chin downward, important for postural control and movement stability.

  • Assists in Deep Breathing: Works with other neck muscles to elevate the ribcage during respiration.

The SCM is crucial for head and neck mobility, balance, and upper body posture.

Signs and Symptoms

Individuals with SCM trigger points often report:

  • Pain in the Neck and Head That Feels Like a "Tight Band" or Deep Ache

  • Headaches That Travel to the Forehead, Temples, or Behind the Eyes (Can Resemble Migraines or Sinus Pain)

  • Dizziness or Balance Issues (Can Feel Like Lightheadedness or a "Floating" Sensation)

  • Jaw or Ear Pain That Worsens with Talking, Chewing, or Clenching the Jaw

  • Tightness or Discomfort in the Neck That Limits Head Rotation or Flexion

  • Pain or Stiffness That Worsens with Forward Head Posture, Driving, or Prolonged Screen Use

Pain worsens with stress, poor posture, repetitive head movements, or excessive neck strain.

Perpetuating Factors

Common causes of SCM trigger points include:

  • Forward Head Posture (Common in Desk Workers, Gamers, and Smartphone Users)

  • Chronic Stress or Anxiety (Leads to Increased Neck and Shoulder Tension)

  • Sleeping in an Awkward Position (Can Cause Morning Stiffness and Neck Pain)

  • Frequent Talking, Singing, or Jaw Clenching (Can Cause Overuse of the SCM and Related Muscles)

  • Whiplash Injuries or Sudden Head Movements (Can Trigger or Aggravate Existing Muscle Tension)

Trigger Point Referral Pattern

Trigger points in the SCM refer pain to:

  • The forehead, temples, and behind the eyes (Can Mimic Tension Headaches or Migraines)

  • The jaw and around the ear (Mistaken for TMJ Dysfunction or Ear Pain)

  • The side of the neck and collarbone (Can Resemble Trapezius Strain or Cervical Nerve Irritation)

Pain from this muscle is often confused with migraines, sinus pressure, or cervical radiculopathy.

Differential Diagnosis

SCM trigger points may be mistaken for:

  • Tension Headaches (Dull, Aching Pain That Wraps Around the Head, Worsens with Stress or Poor Posture)

  • Migraines (Severe, Pulsating Headaches That May Include Light Sensitivity and Nausea)

  • Cervical Radiculopathy (Neck Pain That Radiates to the Shoulder and Arm Due to Nerve Compression)

  • Vestibular Dysfunction (Dizziness and Balance Issues, Can Be Mistaken for Inner Ear Disorders)

  • TMJ Dysfunction (Jaw Pain and Clicking, Often Exacerbated by Stress or Bruxism)

A thorough cervical spine, jaw, and postural assessment is necessary to rule out these conditions.

Associated Trigger Points

SCM trigger points often co-exist with:

  • Upper Trapezius (Neck and Shoulder Tension, Common in Postural Strain and Chronic Stress)

  • Suboccipital Muscles (Base of the Skull Pain, Contributes to Tension Headaches and Upper Neck Stiffness)

  • Splenius Capitis (Neck and Head Pain, Can Mimic Migraines or Sinus Issues)

  • Masseter (Jaw and Facial Pain, Common in Teeth Clenchers and TMJ Sufferers)

Anatomy and Innervation

Muscle Origin Insertion Innervation
Sternocleidomastoid (SCM) Manubrium of sternum, medial clavicle Mastoid process of temporal bone Accessory nerve (CN XI) and cervical spinal nerves (C2–C3)

The SCM is innervated by the accessory nerve (cranial nerve XI) and cervical spinal nerves (C2–C3), which also control head movement, neck posture, and breathing mechanics.

Patient Examination

A comprehensive examination should include:

  • Palpation: Identify tender nodules along the side of the neck, jawline, and collarbone.

  • Resisted Neck Rotation Testing: Assess pain and weakness when turning the head against resistance.

  • Postural Analysis: Look for forward head posture, rounded shoulders, or excessive neck tension.

  • Jaw and TMJ Function Testing: Rule out clenching, grinding, or jaw dysfunction that may contribute to SCM tension.

Corrective Actions

Dry Needling

  • Dry needling can release trigger points in the SCM, reducing neck stiffness and improving head mobility.

Manual Therapy

  • Trigger Point Release: Apply gentle sustained pressure along the jawline, neck, and clavicle.

  • Myofascial Release: Helps improve circulation and reduce muscle tension in the cervical region.

Stretching

  • SCM Stretch: Tilt the head to one side while turning the chin slightly upward to stretch the opposite SCM.

  • Neck Rotation Stretch: Rotate the head slowly side to side to improve mobility and reduce stiffness.

Strengthening Exercises

  • Chin Tucks (Neck Postural Training): Helps reduce forward head posture and improve cervical alignment.

  • Scapular Retraction Drills: Strengthens the upper back to counteract excessive neck strain.

Postural and Behavioral Adjustments

  • Avoid Prolonged Forward Head Posture (Keep Screens at Eye Level to Reduce Neck Strain)

  • Use Proper Ergonomics While Sitting (Ensure Good Posture and Shoulder Alignment)

  • Practice Deep Diaphragmatic Breathing (Reduces Chronic Neck and Upper Back Tension)

Conclusion

The SCM plays a crucial role in head movement, postural control, and upper cervical stability, but trigger points in this muscle can cause significant headaches, dizziness, jaw pain, and neck stiffness. By incorporating dry needling, manual therapy, stretching, and postural correction, individuals can reduce pain, improve mobility, and prevent chronic neck dysfunction.

➡️ Learn more about Trigger Points

➡️ Explore our Trigger Point Index

Sources:

  • Travell, J. G., & Simons, D. G. (1983). Myofascial Pain and Dysfunction: The Trigger Point Manual (2nd ed.). Williams & Wilkins.

  • Simons, D., & Travell, J. (1999). The Trigger Point Manual, Volume 2: The Lower Extremities. Williams & Wilkins.